Stock monitoring

ABSTRACT

System(s) and method(s) for stock monitoring are provided. Stock monitoring system(s) may include, e.g., a housing, one or more doors disposed in or on the housing, a sensor for sensing the condition of the door(s) and providing a door closed signal indicative of the door(s) having been closed by a user; one or more containers for stock items, located within the housing, the or each container having associated therewith a weight sensor for providing a weight signal indicative of the current weight of the container, and control circuitry, coupled for communication with the weight sensor(s). Method(s) may include, e.g., receiving a door closed signal; receiving one or more weight signals; and determining, for the or each container, the number of stock items removed from the container(s) by the user, from the weight signal(s) occurring during a predetermined sensing period, the predetermined sensing period being dependent upon the door closed signal.

This patent application claims priority to, and is a continuation of,U.S. patent application Ser. No. 12/300,121, filed on Nov. 7, 2008 nowU.S. Pat. No. 8,229,802, which claims benefit of prior filed PCT PatentApplication No. PCT/EP2007/004065, filed May 8, 2007, which claimspriority to Great Britain Patent Application No. 0609101.1, filed May 8,2006. These prior patent applications are hereby incorporated herein byreference for all purposes.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to stock monitoring techniques, and moreparticularly to improving the accuracy and functionalities of electronicstock monitoring.

2. Discussion of the Related Art

In prior art systems, the amount of stock retrieved or removed fromstorage has been determined from changes in weight measurements for abin or container for parts, knowing the unit weight of the part.

GB2299074A discloses a monitoring system for a storage system,comprising a plurality of bins or other storage means 10 containingstock, comprises sensing means 12 associated with the storage means 10to monitor the contents of the storage means 10 and periodically togenerate signals indicative of the contents of the storage means 10 andprocessing means 13 adapted to receive the signals of the contents ofthe storage means 10 and to compare the measured contents of eachstorage means 10 with a respective predetermined level of contents and,if the measured contents has fallen below the predetermined level ofcontents, to generate a signal to instigate an order to replenish thestock in the respective storage means 10.

However, a problem with such systems is that in order to measure stockmovement from bins, weight sensors are read continuously; as weightsensors are subject to drift in their output readings, there is thesignificant possibility of miscounting stock quantities, especially incases where the unit weight of the stock items is small.

SUMMARY OF THE INVENTION

This invention concerns systems and methods for providing monitoring ofquantities of stock in an accurate and preferably secure manner, instorage environments where hand-portable stock items can be stored andaccessed by a user or, more typically, a multitude of different users oremployees. Such storage environments are typically found atmanufacturing and other sites.

According to one aspect of the invention there is provided a methodcarried out in a stock monitoring system, the stock monitoring systemcomprising: a housing, one or more doors disposed in or on the housing,a sensor for sensing the condition of the door(s) and providing a doorclosed signal indicative of the door(s) having been closed by a user,one or more containers for stock items, located within the housing, theor each container having associated therewith a weight sensor forproviding a weight signal indicative of the current weight of thecontainer, and control circuitry, coupled for communication with theweight sensor(s); wherein the method comprises (a) receiving a doorclosed signal; (b) receiving one or more weight signals; (c)determining, for the or each container, the number of stock itemsremoved from the container(s) by the user, from the weight signal(s)occurring during a predetermined sensing period, the predeterminedsensing period being dependent upon the door closed signal.

Preferably, the predetermined sensing period comprises a firstpredetermined time period after the door closed signal. Preferably, thefirst predetermined time period is about 30 to about 90 seconds, forexample about 60 seconds.

Preferably, (c) comprises, for the or each container, determining acurrent average weight of the container by averaging the weight signalsover the predetermined sensing period; determining the weight differencefor the container, the weight difference being the difference betweenthe current average weight and the previously determined average weight;and dividing the weight difference by a weight unit stored in memory inassociation with an identifier for the container, thereby obtaining thenumber of stock items removed from the container by the user.

Preferably, the stock monitoring system further comprises a user IDsensor, adapted to be activated by a user and the method furthercomprises: (d) obtaining a user ID from the user ID sensor uponactivation by a user; (e) determining if the user ID obtained is valid.The user ID sensor may be a swipe card reader, and (d) comprisesextracting a user ID from a swipe card upon swiping by a user.Alternatively, the user ID sensor is a Dallas key sensor, and (d)comprises extracting a user ID from a Dallas key upon activation of theDallas key sensor by a user using his Dallas key.

Preferably, the stock monitoring system further comprises one or moreelectrically controlled locks associated with the door(s), the lock(s)being electrically controllable such that the door(s) are in either alocked or releasable condition, the control circuitry being coupled forcommunication with the locks. The method may further comprise: (f) ifdoor open conditions are met, priming the doors for opening, whereby thedoor(s) are in said releasable condition. In the alternative, (f)comprises: (f′) if door open conditions are met, causing the door(s) toopen, for example, to rotate to an open position. The door openconditions may comprise: (A) the obtained user ID is a valid ID, (B) theuser ID obtained is different from the previously obtained user ID; and(C) the predetermined sensing period has elapsed; wherein thepredetermined sensing period comprises a second predetermined timeperiod after the door closed signal, different from the firstpredetermined time period. Alternatively, the door open conditionscomprise: (D) the obtained user ID is a valid ID, (E) the user IDobtained is the same as the previously obtained user ID; and (F) thepredetermined sensing period has not elapsed; wherein the predeterminedsensing period comprises a second predetermined time period after thedoor closed signal, different from the first predetermined time period.Preferably, the second predetermined time period is about 10 to about 30seconds, for example about 15 seconds.

Preferably, the method further comprises: (g) if the door(s) have notbeen opened by the user with a third predetermined time period after thedoors have been primed for opening, activating the lock(s) so that thedoor(s) are in a locked condition. Preferably, the third predeterminedtime period is about 20 seconds to about 40 seconds, and is for example30 seconds.

The doors comprise exterior doors. Each door may provide user access toa single container or to multiple containers.

Alternatively, the housing includes one or more drawers; each drawerhaving one or more compartments, and the doors comprise or include thelid(s) of the compartment(s).

In one embodiment, a single weight sensor is associated with a pluralityof bins and/or compartments and provides a weight signal indicative ofthe combined weight of the plurality of bins or compartments.

The method may further comprise (h) obtaining, periodically or inresponse to user input, for one or more of the containers, an absoluteweight reading from the weight sensor associated with the container,thereby obtaining the number of stock items in the container.

The method step (d) may include: determining whether the user ID sensedby the user ID sensor is a user ID of a first type, for users removingstock items, or a user ID of a second type, for users restocking thehousing with stock items. In this embodiment, the method preferablyfurther includes (i) if it is determined the obtained user ID is of thesecond type, determining, for the or each container, after a door closedsignal is received, the number of stock items added thereto by the userperforming restocking; and (j) transmitting the number(s) of stock itemsto a server; and (k) storing number(s) of stock items in a file on theserver.

Preferably, the stock control system further includes a display unit,the display unit including a indicator in a first colour, e.g. red, anindicator in a second colour, e.g. amber, and one or more indicators,including a main indicator, in a third colour, e.g. green, wherein themethod preferably includes (l) illuminating the main indicator in thesystem ready state, in which a user ID sensing is awaited; and/or (m) ifit is determined that an obtained user ID is not valid, illuminating theindicator in the second colour for a period, e.g. about 4 seconds, priorto illuminating the main indicator; and/or (n) if it is determined thatan obtained user ID is valid, illuminating said one or more indicatorsin the third colour, and/or (o) in response to a door closed signal,switching off said one or more indicators in the third colour other thanthe main indicator, and illuminating the indicator in the second colour,and/or (p) following a door closed signal, and in response to the weightsensor reading being successfully transmitted, switching off saidindicator in the second colour.

According to another aspect of the invention there is provided a stockmonitoring system when suitably programmed for carrying out the methodof any of claims 1 to 4 of the appended claims, the stock monitoringsystem comprising: a housing, one or more doors disposed in or on thehousing, a sensor for sensing the condition of the door(s) and providinga door closed signal indicative of the door(s) having been closed by auser; one or more containers for stock items, located within thehousing, the or each container having associated therewith a weightsensor for providing a weight signal indicative of the current weight ofthe container, and control circuitry, coupled for communication with theweight sensor(s).

According to another aspect of the invention there is provided a stockmonitoring system when suitably programmed for carrying out the methodof any of claim 5, 6 or 7 of the appended claims, the stock monitoringsystem comprising: a housing, one or more doors disposed in or on thehousing, a sensor for sensing the condition of the door(s) and providinga door closed signal indicative of the door(s) having been closed by auser; one or more containers for stock items, located within thehousing, the or each container having associated therewith a weightsensor for providing a weight signal indicative of the current weight ofthe container, control circuitry, coupled for communication with theweight sensor(s), and a user ID sensor, adapted to be activated by auser.

According to another aspect of the invention there is provided a stockmonitoring system when suitably programmed for carrying out the methodof any of claims 8 to 22 of the appended claims, the stock monitoringsystem comprising: a housing, one or more doors disposed in or on thehousing, a sensor for sensing the condition of the door(s) and providinga door closed signal indicative of the door(s) having been closed by auser; one or more containers for stock items, located within thehousing, the or each container having associated therewith a weightsensor for providing a weight signal indicative of the current weight ofthe container, control circuitry, coupled for communication with theweight sensor(s), a user ID sensor, adapted to be activated by a user,and one or more electrically controlled locks associated with thedoor(s), the lock(s) being electrically controllable such that thedoor(s) are in either a locked or releasable condition, the controlcircuitry being coupled for communication with the locks.

According to another aspect of the invention there is provided a stockmonitoring system, comprising: a housing, one or more doors disposed inor on the housing, a sensor for sensing the condition of the door(s) andproviding a door closed signal indicative of the door(s) having beenclosed by a user; one or more containers for stock items, located withinthe housing, the or each container having associated therewith a weightsensor for providing a weight signal indicative of the current weight ofthe container, control circuitry, coupled for communication with theweight sensor(s); wherein the control circuitry is operable for (a)receiving a door closed signal; (b) receiving one or more weightsignals; (c) determining, for the or each container, the number of stockitems removed from the container(s) by the user, from the weightsignal(s) occurring during a predetermined sensing period, thepredetermined sensing period being dependent upon the door closedsignal.

Preferably, the predetermined sensing period comprises a firstpredetermined time period after the door closed signal. Preferably, thefirst predetermined time period is about 30 to about 90 seconds, forexample about 60 seconds.

Preferably, (c) comprises for the or each container, determining acurrent average weight of the container by averaging the weight signalsover the predetermined sensing period; determining the weight differencefor the container, the weight difference being the difference betweenthe current average weight and the previously determined average weight;dividing the weight difference by a weight unit stored in memory inassociation with an identifier for the container, thereby obtaining thenumber of stock items removed from the container by the user.

Preferably, the stock monitoring system further comprises a user IDsensor, adapted to be activated by a user and, wherein the controlcircuitry is operable for: (d) obtaining a user ID from the user IDsensor upon activation by a user; (e) determining if the user IDobtained is valid. The user ID sensor may be a swipe card reader, and(d) comprises extracting a user ID from a swipe card upon swiping by auser. Alternatively, the user ID sensor is a Dallas key sensor, and (d)comprises extracting a user ID from a Dallas key upon activation of theDallas key sensor by a user using his Dallas key.

Preferably, the stock monitoring system further comprises one or moreelectrically controlled locks associated with the door(s), the lock(s)being electrically controllable such that the door(s) are in either alocked or releasable condition, the control circuitry being coupled forcommunication with the locks. The control circuitry may be operable for:(f) if door open conditions are met, priming the doors for opening,whereby the door(s) are in said releasable condition. Alternatively, thecontrol circuitry may be operable for (f′) if door open conditions aremet, causing the door(s) to open, for example, to rotate to an openposition. The door open conditions may comprise: (A) the obtained userID is a valid ID, (B) the user ID obtained is different from thepreviously obtained user ID; and (C) the predetermined sensing periodhas elapsed; wherein the predetermined sensing period comprises a secondpredetermined time period after the door closed signal, different fromthe first predetermined time period. Alternatively, the door openconditions comprise: (D) the obtained user ID is a valid ID, (E) theuser ID obtained is the same as the previously obtained user ID; and (F)the predetermined sensing period has not elapsed; wherein thepredetermined sensing period comprises a second predetermined timeperiod after the door closed signal, different from the firstpredetermined time period. Preferably, the second predetermined timeperiod is about 10 to about 30 seconds, for example about 15 seconds.

The control circuitry may be operable for: (g) if the door(s) have notbeen opened by the user with a third predetermined time period after thedoors have been primed for opening, activating the lock(s) so that thedoor(s) are in a locked condition. Preferably, the third predeterminedtime period is about 20 seconds to about 40 seconds, and is for example30 seconds.

The doors comprise exterior doors. Each door may provides user access toa single container or to multiple containers.

Alternatively, the housing includes one or more drawers; each drawerhaving one or more compartments, and the doors comprise or include thelid(s) of the compartment(s).

In one embodiment, a single weight sensor is associated with a pluralityof bins and/or compartments and provides a weight signal indicative ofthe combined weight of the plurality of bins or compartments.

The control circuitry may be operable for: (h) obtaining, periodicallyor in response to user input, for one or more of the containers, anabsolute weight reading from the weight sensor associated with thecontainer, thereby obtaining the number of stock items in the container.

The control circuitry may be operable such that (d) includes:determining whether the user ID sensed by the user ID sensor is a userID of a first type, for users removing stock items, or a user ID of asecond type, for users restocking the housing with stock items.Preferably, the control circuitry is operable for: (i) if it isdetermined the obtained user ID is of the second type, determining, forthe or each container, after a door closed signal is received, thenumber of stock items added thereto by the user performing restocking;and (j) transmitting the number(s) of stock items to a server; and (k)storing number(s) of stock items in a file on the server.

Preferably, the stock control system further includes a display unit,the display unit including a indicator in a first colour, e.g. red, anindicator in a second colour, e.g. amber, and one or more indicators,including a main indicator, in a third colour, e.g. green. Preferably,control circuitry is operable for: (l) illuminating the main indicatorin the system ready state, in which a user ID sensing is awaited; and/or(m) if it is determined that an obtained user ID is not valid,illuminating the indicator in the second colour for a period, e.g. about4 seconds, prior to illuminating the main indicator; and/or (n) if it isdetermined that an obtained user ID is valid, illuminating said one ormore indicators in the third colour, and/or (o) in response to a doorclosed signal, switching off said one or more indicators in the thirdcolour other than the main indicator, and illuminating the indicator inthe second colour, and/or (p) following a door closed signal, and inresponse to the weight sensor reading being successfully transmitted,switching off said indicator in the second colour.

According to another aspect of the invention there is provided arecordable, rewritable or recorded medium having recorded or storedthereon machine readable data defining or transformable intoinstructions for execution by processing circuitry and corresponding toat least the steps of the methods set out in any of claims 1 to 23 ofthe appended claims.

According to another aspect of the invention there is provided a servercomputer incorporating a communications device and a memory device andbeing adapted for transmission on demand or otherwise of data definingor transformable into instructions for execution by processing circuitryand corresponding to at least the steps of any of claims 1 to 23 of theappended claims.

Using techniques according to the invention, rather than continuouslysensing weight measurements from weight sensors or load cells, themeasurements are taken only for a relatively short period after thedoors of the housing have been closed by a user (typically after removalof stock by the user). Weight measurements are averaged over a period ofone minute, or at least over a period of at least 15 seconds or so. Inthis way, measurements are more accurate and effects of weightmeasurement drift are reduced or eliminated. So the accuracy in countingquantities of stock removed is increased, in some cases exceeding 99%accuracy.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments of the invention will now be described in detail, by way ofexample, with reference to the accompanying drawings, in which:

FIGS. 1A and 1B shows a housing or cabinet employed in the stockmonitoring system according to a first embodiment of the invention;

FIGS. 2A and 2B illustrate the effect of weight sensor drift;

FIG. 3 is a schematic block diagram showing the main electricalcomponents in the stock monitoring system according to the firstembodiment; and

FIGS. 4A and 4B are a flow chart showing the main processing steps andoperations in implementing stock monitoring according to the firstembodiment;

FIG. 5 is a schematic block diagram showing the main electricalcomponents in the stock monitoring system according to a secondembodiment of the invention;

FIGS. 6A and 6B are a flow chart showing the main processing steps andoperations in implementing stock monitoring according to the secondembodiment;

FIGS. 7A-7C shows a housing or cabinet employed in the stock monitoringsystem according to a third embodiment of the invention, employingcompartmentalised drawers, with (a) a lateral front view of the drawers,and (b) plan and (c) side views of a drawer;

FIG. 8 is a schematic block diagram showing the main electricalcomponents in the stock monitoring system according to the thirdembodiment; and

FIGS. 9A-9C are a flow chart showing the main processing steps andoperations in implementing stock monitoring according to the thirdembodiment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

In the following, like numerals will be used to denote like elements.Certain techniques disclosed in GB2299074A may be employed inimplementing the present invention, as appropriate, except as describedhereinafter. Stock items may be, for example, automotive components,electrical components or fasteners and PPE and MRO consumables. Ingeneral every item contained in each particular bin 10 will beidentical, but this is not essential. Equally, “stock items” may referto consumable products or parts, re-usable products or parts, finishedproducts or articles, tools, items of clothing, or any other item thatis stored in pluralities and may be used or re-used by one or morepersons.

FIG. 1 shows a housing or cabinet employed in the stock monitoringsystem according to a first embodiment of the invention, (a) in frontview and (b) in side view. The cabinet 100 comprises a main body 102 anda pair of doors 104 having transparent (e.g. glass, Perspex) panels 105.Here, two doors are illustrated, but 1, 3 or more may be used. The doors104 and main body 102 are suitably made of steel, but any other suitablystrong and rigid material may be used.

A plurality of shelves 106 are provided within the cabinet 100, on eachof which are mounted a plurality of storage bins 108 (here, forsimplicity, only one shelf 106 is shown supporting bins). Each bin 108sits on top of a weight sensor, suitably comprising a load cell 110 asis known to persons skilled in the art, each load cell 110 providing ananolog signal indicating the weight of the bin 108 it is supporting. (inalternative embodiments, there may be one load cell 110 for two or morebins 108). Each bin 108 stores stock items 112. Stock may be, forexample, automotive components, electrical components or fasteners. Ingeneral every item contained in each particular bin 108 will beidentical.

Provided at the top right corner of the cabinet 100 is a swipe cardreader 114 which is able to read swipe cards belonging to users (e.g.factory employees) and, depending on the ID extracted from the swipecard, cause the doors to be released for opening by the user, or not.Although, in this embodiment, a swipe card reader is used, it will beappreciated that other means of obtaining the user ID may be used,including, for example, IR or short range radio based portable devices,barcode readers, RFID systems, biometric (e.g. fingerprint, retina scan)devices, and so forth. Dalls keys may also be used.

FIG. 2 illustrates the effect of weight sensor drift. In FIGS. 2( a) and(b), the weight signal output by the load cell 110 against time t isindicated by traces T and T′ respectively, the levels L1 to L4 indicatethe transition between different numbers (quantities) being recorded asbeing within the respective bin 108.

As shown, although highly exaggerated, the traces T, T′ are not flat(constant), but drift. In the case of FIG. 2( a) the stock items 112 areof a higher unit weight than those for FIG. 2( b). Thus, for FIG. 2( a),the drift does not cause a false reading, but in FIG. 2( b), the driftis such as to pass through threshold level L3, meaning that the weightsignal sent by the load cell corresponds to a quantity in the bin thatis false, i.e. is one less than the actual value.

For the cabinet-based system with doors (FIG. 1), there are two variantsof the system. The first variant, shown in FIGS. 3 and 4, has a separatemultiplexor 302, Vlinx Box 310 and controller 316. The second variant,shown in FIGS. 5 and 6, is essentially the same as the first, exceptthat it has one controller (516) replacing multiplexor 302, Vlinx Box310 and controller 316. In a first variant, the locks to the doors inare primed for release and have to be pushed to be released. In a secondvariant, the locks to the doors in are released automatically when thecard is swiped.

FIG. 3 is a schematic block diagram showing the main electricalcomponents in the stock monitoring system according to a firstembodiment of the invention. Each load cell 110 (only one of which isshown) is coupled to a multiplexer 302. The load cells 110 send analogweight readings to the multiplexer 302 and receive LED status signalsfrom the multiplexer 302. As indicated by the key 304, each load cell110 incorporates or is coupled to and associated with, a simple statusindicator (e.g. using LEDs), including amber left LED 306 and a rightred LED 308. The status currently being indicated by the LEDs is as setout in the diagram (key 304).

Multiplexer 302 averages weight readings received from the load cell(s)110 and converts the analog average reading to a digital reading. Themultiplexer 302 sends load cell digital readings and multiplexer statussignals to a serial-to-Ethernet conversion unit 310, and receivestherefrom, when appropriate, calibration requests (e.g. when an absoluteweight measurement of one or more of the bins 108 is performed). Theserial-to-Ethernet conversion unit 310 suitably comprises a VlinxEthernet serial server available from B&B Electronics Ltd, Co. Galway,Ireland (see, for example (a)http://www.bb-elec.com/product_family.asp?familyid=2 and (b)http://www.bb-elec.com/bb-elec/literature/ESP904-4105ds.pdf). Theserial-to-Ethernet 310 connects, configures, and communicates withserial devices over Ethernet using a single IP address. The unit usesDB9 male serial connectors and supports RS-232, RS-422 and RS-485. Theserial-to-Ethernet conversion unit 310 transmits load cell digitalreadings and multiplexer status signals to a network switch 312 andreceives therefrom online/offline request signals.

The network switch 312 is of the type well known to persons skilled inthe art for implementing Ethernet based LAN or WAN systems, enablingcomputers to communicate using TCP/IP, Ethernet and other protocols.

Referring briefly to FIG. 1, the doors 104 can be locked usingelectrically controlled locks (not shown in FIG. 1). These locks are ofthe type known in the art (e.g. part no. INV02, available fromInventor-e Ltd). The locks are designated 314 in FIG. 3. In thisembodiment, these are activated (locking doors 104 (FIG. 1)) after bothdoors are shut.

The locks 314 send lock status signals to a door controller 316. Also,the locks 314 receive control signals from the door controller 316 asfollows:

-   -   “Set door lock”    -   “Timeout” (after set period of time to relock doors), and    -   “Prime doors for release”.        The door controller 316 may be any suitable microprocessor-based        controller known in the art.

The door controller 316 sends lock status signals to the network switch312 and receives therefrom, when appropriate, reboot messages.

The network switch 312 is further coupled to a rack PC 318. This is acomputer with standard (PC) architecture, with mountings,components/interfaces and specifications for use in industrialenvironments. Rack PC 318 suitably

-   -   stores a database (of user IDs) for controlling door access    -   processes load cell readings and converts them to quantities of        parts/stock items    -   stores Part IDs, part unit weights, user IDs and location IDs.    -   Optionally, the rack PC 318 is coupled to a web server 329 and        sends stored and derived data thereto. In turn, the web server        320 is able to supply on demand (e.g. over internet and subject        to password access) reports on data obtained from the rack PC,        enabling a remote user (e.g. supplier) to view reports and        download (e.g. into a suitable software package such as MS        Excel).

The link between the multiplexer 302 and the rack PC 318 may be a wiredlink, using suitable network hardware and protocols. Alternatively, asuitable wireless link may be used, e.g. GPRS.

Referring to the load cells 110 in FIG. 3, although the display has beenindicated as a simple LED display, in an alternative embodiment the loadcells incorporate or are associated with a display (e.g. LCD) thatdisplays the current total quantity of items in the respective bin 108based on data received from the rack PC 318.

FIG. 4 is a flow chart showing the main processing steps and operationsin implementing stock monitoring according to the first embodiment ofthe invention. Commencing at 402, here the stock monitoring system is ina “system ready” state, ready for a user to attempt to access thecabinet 100. In addition (see bottom left of FIG. 4), mounted in or onthe cabinet 100, coupled to the door controller 316 and visible to theuser is a user display incorporating a number of LEDs. This includesupper red LED (1), a middle amber LED (2) and three green lower LEDS(3), (4), (5). In the “system ready” state, green LED (3) isilluminated.

At 404, a user swipes his swipe card through the card reader (114 inFIG. 1). Then, the extracted card (user) ID is sent to the rack PC 318,and a card acceptance/rejection message returned (depending on whetherthe user ID is an authorised/valid ID in the database stored on rack PC318).

The two possibilities are indicated at 406. As indicated at 408, if thecard (ID) is not valid, then doors 104 are not primed for opening, therack PC 318 send a message to the door controller 316 to display apredetermined indication. At 408 (FIG. 4), an LED status message is sentto the door controller to illuminate LED (2) for 4 seconds, prior toreturning to the “system ready” state, with only LED (3) illuminated.

If the determination was that the card (user) ID was valid (406), therack PC 318 then sends (410) a message to the door controller 316 toprime the doors for opening (i.e. the locks 314 are electricallyreleased; and the user can simply push the doors inward to release alatch (not shown), before opening the doors). Also, green LEDs (3), (4)and (5) are illuminated. As indicated at 412, if the user has not pushedthe doors to open within 30 seconds, processing returns to 408.

Once the user does push the doors to open within 30 seconds, a beacon(LED) is set (414) flashing (signal to door controller 316) until theuser shuts the door. At 416 a door closed signal has been received,indicating that the user has closed the doors. A message is sent to thedoor controller 316 to cease flashing the beacon. LEDs (4) and (5) areswitched off, LED (2) (amber) illuminated, and the locks are activatedto lock the doors.

Also at 416, a request reading signal is sent to the multiplexer 302, inresponse to which load cell readings are returned. Then, at 418, updatedmultiplexer (digital weight) readings are sent to the rack PC 318, and aLED and lock status signal is sent to the door controller 316 (i.e.returning the system to the “system ready” state.

As indicated at 420, the doors are now locked, and LED (3) (“systemready”) illuminated.

The above-described process is applicable when a card is swiped after apredetermined interval (e.g. 15 seconds) after the doors were lastclosed. However, if there is a card swipe (422) within that period, acheck (424) is made to determine whether it was by the same user as theprevious occasion. If not, processing moves to 418, and if so,processing moves to 410.

Another procedure is indicated at 426, 428. This may be used, forexample, if the rack PC 318 is for some reason non-operational. Here, anoverride key is used in the swipe card reader 114 (FIG. 1), so that thedoors can be opened (426). Then, the multiplexer 302 reads the weightreadings from the load cells 110, calculates the numbers of stock itemsremoved, and books (stores in database in memory) the amount to therecorded owner of the key. Processing then proceeds to 420.

FIG. 5 is a schematic block diagram showing the main electricalcomponents in the stock monitoring system according to a secondembodiment of the invention. This is the same as the first embodiment,except as described hereafter. Each load cell 110 (only one of which isshown) is coupled to a secondary controller 516. The load cells 110 sendanalog weight readings to the secondary controller 516 and receive LEDstatus signals from the secondary controller 516. As indicated by thekey 504, each load cell 110 incorporates or is coupled to and associatedwith, a simple status indicator (e.g. using LEDs), including amber leftLED 506 and a right red LED 508. The key 504 is the same as key 304 inFIG. 3.

Secondary controller 516 averages weight readings received from the loadcell(s) 110 and converts the analog average reading to a digitalreading. The secondary controller 516 transmits load cell digitalreadings and multiplexer status signals to a network switch 512 andreceives therefrom online/offline request signals.

The secondary controller 516 incorporates or implements a multiplexor(not shown; see FIG. 3) and an access controller (not shown).

Referring briefly to FIG. 1, the doors 104 can be locked usingelectrically controlled locks, designated 514 in FIG. 5.

The locks 514 send lock status signals to a secondary controller 516.Also, the locks 514 receive control signals from the secondarycontroller 516—

-   -   “Set door lock”    -   “Timeout” (after set period of time to relock doors), and    -   “Release Door Lock”.        The secondary controller 516 may be any suitable        microprocessor-based controller known in the art, for example        model/part no. SS01, available from Inventor-e Ltd.

The secondary controller 516 sends lock status signals to the networkswitch 512 and receives therefrom, when appropriate, reboot messages.

The network switch 512 is further coupled to a Controlling Software PC518 (also referred to herein as Rack PC). This is a computer withstandard (PC) architecture, with mountings, components/interfaces andspecifications for use in industrial environments. Controlling SoftwarePC 518 suitably

-   -   stores a database (of user IDs) and (optionally) charge code        ID's for controlling door access    -   processes load cell readings and converts them to quantities of        parts/stock items    -   stores Part IDs, part unit weights, user IDs and location IDs.

Optionally, the Controlling Software PC 518 is coupled to a web server520 and sends stored and derived data thereto. In turn, the web server520 is able to supply on demand (e.g. over internet and subject topassword access) reports on data obtained from the rack PC, enabling aremote user (e.g. supplier) to view reports and download (e.g. into asuitable software package such as MS Excel).

The link between the secondary Controller 516 and the ControllingSoftware PC 518 may be a wired link, using suitable network hardware andprotocols. Alternatively, a suitable wireless link may be used, e.g.GPRS.

FIG. 6 is a flow chart showing the main processing steps and operationsin implementing stock monitoring according to an embodiment of theinvention. Commencing at 602, here the stock monitoring system is in a“system ready” state, ready for a user to attempt to access the cabinet100. In addition (see bottom left of FIG. 6), mounted in or on thecabinet 100, coupled to the secondary controller 516 and visible to theuser is a user display incorporating a number of LEDs. This includesupper red LED (1), a middle amber LED (2) and three green lower LEDS(3), (4), (5). In the “system ready” state, green LED (3) isilluminated.

At 604, a user swipes his swipe card through the card reader (114 inFIG. 1). Then, the extracted card (user) ID is sent to the ControllingSoftware PC 518, and a card acceptance/rejection message returned(depending on whether the user ID is an authorised/valid ID in thedatabase stored on Controlling Software PC 518).

The two possibilities are indicated at 606. As indicated at 608 (seeFIG. 6( d)), if the card (ID) is not valid, then doors 104 are relocked,the Controlling Software PC 518 sends a message to the secondarycontroller 516 to display a predetermined indication. An LED statusmessage is sent to the door controller to illuminate LED (2) for 4seconds, prior to returning to the “system ready” state, with only LED(3) illuminated.

If the determination was that the card (user) ID was valid (606),depending on configuration, the user may be required to enter a chargecode (see FIG. 6( c)). If this is setup, the user is asked (607) forthis charge code, or if not, the system releases the locks (610). At 607the user enters a charge code using the input device 116. The latter canbe a number of said devices including bar code reader, touch screen,keypad. Then, the extracted charge code is sent to the ControllingSoftware PC 518, and a charge code acceptance/rejection message returned(depending on whether the charge code ID is an authorised/valid chargecode in the database stored on Controlling Software PC 518).

The two possibilities are indicated at 609. As indicated at 607, if thecharge code (ID) is not valid, then doors 104 do not have there locksreleased, the Controlling Software PC 518 sends a message to thesecondary controller 516 to display a predetermined indication. At 607(FIG. 6( c)), if the user doesn't enter a charge code within 15 seconds,an LED status message is sent to the secondary controller 516 toilluminate LED (2) for 4 seconds, prior to returning to the “systemready” state, with only LED (3) illuminated. If the determination wasthat the charge code was valid (609) the system proceeds to (610).

The Controlling Software PC 518 then sends (610) a message to thesecondary controller 516 to release the locks (i.e. the locks 514 areelectrically released; and the user can simply pull the doors outward).Also, green LEDs (3), (4) and (5) are illuminated. As indicated at 612,if the user has not pushed the doors to open within 30 seconds,processing returns to 608.

Once the user does open the doors within 30 seconds, a beacon (LED) isset flashing 614 (signal to secondary controller 516) until the usershuts the door. At 616 a door closed signal has been received (see FIG.6( f)), indicating that the user has closed the doors. A message is sentto the secondary controller 516 to cease flashing the beacon. LEDs (4)and (5) are switched off, LED (2) (amber) illuminated, and the locks areactivated to lock the doors.

Also at 616 (FIG. 6( f)), a request reading signal is sent to secondaryController 516, in response to which load cell readings are returned.Then, at 618, updated digital weight readings are sent by secondaryController to the Controlling Software PC 518, and a LED and lock statussignal is sent to the secondary controller 516 (i.e. returning thesystem to the “system ready” state).

As indicated at 620, the doors are now locked, and LED (3) (“systemready”) illuminated.

The above-described process is applicable when a card is swiped after apredetermined interval (e.g. 15 seconds) after the doors were lastclosed. However, if there is a card swipe (622) within that period, acheck (624) is made to determine whether it was by the same user as theprevious occasion. If not, processing moves to 618, and if so,processing moves to 610.

Another procedure is indicated at 626, 628. This may be used, forexample, if the Controlling Software PC 518 is for some reasonnon-operational. Here, a mechanical override key is used, so that thedoors can be opened (626). Then, the Inventor-e Controller 516 reads theweight readings from the load cells 110, calculates the numbers of stockitems removed, and books (stores in database in memory) the amount tothe recorded owner of the key. Processing then proceeds to 620.

FIG. 7 shows a housing or cabinet employed in the stock monitoringsystem according to a third embodiment of the invention, employingcompartmentalised drawers, with (a) a lateral front view of the drawers,and (b) plan and (c) side views of a drawer. As seen in FIG. 7( a), ahousing 700 is in the form of a chest of drawers, each drawer 704 beingopenable by the user using handle 703. The housing 700 is suitablymounted on casters 701. In addition, each drawer 704 has a respectivedrawer LED 707. FIG. 7( b) shows a single drawer 704 from above, thedrawer 704 having a plurality (here 16) compartments, each being coveredby a lockable lid 709. In turn, a lid LED 711 is provided for each lid709, as a status indicator. The drawers 704 may also be lockable.

The side view of a drawer, in FIG. 7( c), shows compartments or bins708, 708′, each containing parts or stock items 712. Each compartment708 has its own associated load cell 710, for sensing weight changes dueto addition/removal of parts. In some cases, a single load cell 710′ maybe provided for measuring weight changes of two or more adjacentcompartments 708′ (in which case the per unit part weight may be thesame or different in the adjacent compartments 708′).

FIG. 8 is a schematic block diagram showing the main electricalcomponents in the stock monitoring system according to the thirdembodiment. This is the same as for the second embodiment, except asdescribed hereafter. In this embodiment, both compartment locks 814 anddrawer locks 815 are provided, which lock compartments 708, 708′ anddrawers 704, respectively, after they have (been) closed. The secondarycontroller 816, incorporates multiplexor 802 and access controller 803.The access controller—

-   -   sends LED status commands to the load cells & compartments,    -   sends signals to the compartment locks to (i) timeout after a        set period to relock a compartment, and (ii) lock/unlock        compartments, and    -   sends signals to the rawer locks to (i) timeout after a set        period to relock a drawer, and (ii) set drawer locks

The access controller 803 sends signals indicating compartment lockstatus and drawer lock status to the network switch 812. In turn, thenetwork switch 812 sends signals indicating compartment lock status anddrawer lock status to the controlling software (CS) PC 818. The CS PC818 sends signals in the other direction to (a) request cancelling of adrawer primed for opening and (b) lock/unlock a compartment.

FIG. 9 is a flow chart showing the main processing steps and operationsin implementing stock monitoring according to the third embodiment. Thisis the same as for the second embodiment, except as described hereafter.Instead of lock/unlock, and other actions in relation to doors, therelevant action is taken in relation to drawers (steps 902, 908, 910,912, 921, 923, 925, 920, 929) or compartments (lids) (steps 914, 919,916).

In this third embodiment, the weight sensor based solution may utilise astandard tool cabinet e.g. Lista, Bott etc., with drawers that arecompartmentalised to provide a high density storage solution with fastaccess. Each drawer has user access control, and there is also userdefined access control at the compartment level. Segmentation of adrawers with the cabinet and use of (i) a weight sensor under the wholesegmented drawer or (ii) a number of weight sensors to cover areas (morethan one compartment) of the drawer, to control multiple dispensing ofthe same item from various compartments, may be employed. Thecompartments have restricted access via transparent openable/lockablelids on each, and the CS PC (Rack PC) records who has accessed thedrawer and the individual compartment opened, using a smart button(Dallas key technology) or graphic user interface on the connected CSPC. The software can determine the part being accessed from its locationand knows the part and the associated piece part weight of the itembeing taken, e.g. 9 grams. After the compartment lid has been closed,the CS PC records movement in inventory, e.g. if it is a 27 gramdecrement in weight it will calculate that three of that particular partfrom that compartment have been taken. The user then moves on to obtaininventory from another compartment in the same drawer, or to anotherdrawer, or simply shuts the drawer to close the transaction. Thisembodiment is ideal for the management of tools and smaller MROcomponents, where a range of products is required to be stored in a highdensity solution.

In the foregoing embodiment, one weight sensor may be used to managemultiple compartments, with the parts or stock items in each of thosemultiple compartments being identical or non-identical. Access controlprovides the software with the part and associated weight, which allowsthe weight sensor to record total weight change across all compartmentsit controls. The software knows the compartment accessed and part thathas been taken, as the access control prevents other compartments frombeing opened until the compartment that has been opened is closed andthe new weight sensor reading has been taken.

In a further embodiment, the storage cabinet is in the form of alocker-style cabinet (not dissimilar to those found in sports centres,clubs and schools). This is similar to the first embodiment, but hasindividual doors to shelves and/or bins, one door per bin or per shelf.This embodiment allows auditable issuance and return control on lockers,rather than having to physically key in the quantity taken or returned,as this relies on trust and user accuracy. Access to individual doors isvia a Dallas (Smart) key, a smart key reader being coupled to the CS PC(rack PC). Supervisors have a master key that will allow access to alldoors and will allow them to set up access to individual doors locally(on site) for their operatives.

Some functionalities of the stock control system will be summarised. Thesystem utilises weight sensor technology to measure inventory(quantities of stock). Doors with enforced access control allow for useridentification. The user swipes his identity card (with or without a PINnumber) and this is validated against a user database. The locks on thestorage cabinet are then ready to be released. In the first embodiment,the doors are then pushed to release the locks. If the doors are notpushed to open (first embodiment) or not pulled to open (secondembodiment), the locks relock after a predetermined period. Thisprevents anyone else entering the cabinet on the identity card of theoriginal person.

Measurements from the weight sensors are ignored with the exception ofanti-tampering reports whilst the cabinet doors are open. Theanti-tampering reports provide data on stock movement while the doorsare open, e.g. if an individual takes an expensive item and replaces itwith a lower value item of the same weight the main reporting systemwould not identify a stock movement against that individual user.However, the stock control system according to the invention reads thebins rapidly, so even the weight of a hand going in to take the itemwould be registered.

Users can take inventory and put it back but measurements taken from theload cells are not utilised within the software until the doors havebeen closed. The measurements from the load cells are then taken for ashort predetermined time (e.g. one minute), and subsequent readings areignored until the doors are opened and closed again. This means thatdrift in the weight sensors is minimised, as the time to read the weightsensors is finite. The quantity values are incremented or decrementedfrom an original absolute value, which is measured when the cabinet isfirst loaded with inventory. Therefore the software only looks forchanges in the weight of the bins over a very short time period and thusminimises the effect of drift, thereby maintaining high levels ofaccuracy on the inventory. The system also has the facility to do newabsolute readings, which calculates the real time total weight of a bin.There is therefore the opportunity to compare or override thedecremented readings from an original absolute value with new absolutereadings.

When the doors have been closed the system reads the weight sensors for15 seconds and does not allow any new users access to the storagecabinet in this period, although the same user can access in thisperiod. This ensures accurate quantity changes and issuance and returnquantities against users, as the system averages out peaks and troughsover this 15 second period to ensure accurate readings are taken. Ifanother user does not swipe, readings will be taken for a one minuteperiod to ensure the most accurate readings are taken. After one minutereadings are ignored until the doors are opened again.

To restock the cabinet a supplier has a restock card. Physically this isthe same as the issuance card (see below) but it identifies the user asa supplier or re-stocker and treats the data differently to materialsbeing placed into cabinet with the issuance card. More particularly:

-   -   1) The issuance card is suitably an end user card and monitors        material taken from the cabinet against individual employees.        When an employee returns stock it is simply deducted from their        account. For example, if an employee swipes and takes three        pairs of gloves and an hour later returns two pairs, the net        usage against their issuance account would be one pair of        gloves.    -   2) The restock card (normally a supplier or third party        outsourced replenishment service) treats items being put into        the cabinet as new stock being introduced and automatically        stores the quantity increases measured after the doors have been        shut in a restock file. This means that an automated proof of        delivery is recorded in computer memory. The cabinet records the        quantities of items put into the cabinet together with the ID of        the person that did the restock and the date and time of the        transaction. This means performance measures can be        automatically generated from the automated data capture

The system collects date and time stamped quantity change data andallocates it to a defined user (restocker or employee requiring issuanceor return). The system then can send this data through, for example, anADSL line or via GPRS. Messages of quantity changes are only sent oneminute after the doors have been closed. This keeps message traffic to aminimum and therefore the cost of message traffic low. However, it meansthat quantity data is dynamically updated and available to remote users.

As used herein, “storage cabinet” refers to any housing or container inwhich bins, compartments, weight sensors, parts, tools or stock itemsare housed, including for example cabinets with doors and shelves orbins, chests of drawers, and locker style cabinets.

Additional particular embodiments are set out below.

1. In a further embodiment, the system further includes a UI in the formof a touch screen, allowing a delivery (quantity of items for restockinga storage cabinet) to be allocated to a delivery note number. Onrestocking the supplier swipes their card through the card readerprovided on the storage cabinet (and coupled directly or indirectly tothe CS PC); the user is then validated and then prompted to enter adelivery note number, for use in database actions. The delivery notenumber can be keyed in via the touch screen or entered by barcodescanning. This allows access into the storage cabinet, and allquantities put into the storage cabinet will be allocated in thedatabase to the delivery note number, as well as to the user. Thisallows delivery to a number of storage cabinets connected to the CS PC,and allows an administrator to validate the delivery against thissupplier's delivery note number. In addition, this embodiment enablesreports to be made available on order fulfillment, supplier performanceand number of “stock outs” per supplier, and the duration of stock outsby supplier.

2. In a further embodiment, in which the system further includes a touchscreen, the user has the ability to display reports of quantities ofitems in other storage cabinets at the current storage cabinet touchscreen, and if the item they are looking for is not available they havethe ability to search from that storage cabinet which user had the lastitem. The user can also access videos (e.g. how to use a product), andor advertising, pictures and COSSH information at the touch screen ofthe storage cabinet.

3. In a further embodiment, in which the system further includes a UI,an Exception Report is accessible, indicating items taken out of JobNumber Scope (i.e. items that should not have been taken for the jobassociated with the job number). A list of parts or items can beallocated to a particular job number/charge code. When a user enters ajob number/charge code, an exception report is generated if the usertakes a part which is outside the scope for that job number/charge code.

4. In a further embodiment, in which the system further includes a touchscreen it may be possible to lock out users from a particular storagecabinet, in order to pre-allocate a product. When a user searches for apart from at a storage cabinet touch screen or kiosk, they have theability to lock a particular storage cabinet for a time frame so that noother users can take that product. Once the user who has locked thestorage cabinet has visited the storage cabinet and swiped their card atthe card reader, the storage cabinet opens. If the user doesn't swipetheir card at the storage cabinet within a predetermined time frame e.g.a number of seconds, or minutes or hours), then that storage cabinetbecomes unlocked again.

5. In a further embodiment, in which the system further includes abarcode reader on, adjacent or near a storage cabinet, and associatedtherewith and coupled to the CS PC, enhanced restocking is provided.Here, there is validation by bar coding of the product to the bar codeon the appropriate bin in the storage cabinet. When the user scans thebar code on the product, the code is sent to the CS PC, and the CS PCresponds with commands to controller to it light up the correct bin toplace the product(s) into. The user then barcode scans the bin to tellthe system which bin it is putting the product into. This bin thenrecords a quantity. The benefit is that it ensures the correct part goesinto the correct location.

6. In a further embodiment, the system, in addition to load celltechnology, further includes a RFID sensor on, adjacent or near astorage cabinet, and associated therewith and coupled to the CS PC. Thissystem is able to enhance processing, to establish part quantity, whenparts, stock items etc. are RFID tagged. When a part is RFID tagged itsunit weight is also stored by the system. When a user takes a part froma bin having a weight sensor underneath it, the system checks that theRFID tag has left the storage cabinet, but also that the weight has beendecremented by the part weight. Where the tag has left the storagecabinet but the weight has not been changed the part is still classed asbeen in the storage cabinet and an exception report can begenerated/viewed, highlighting this problem. Alternatively, if a usertakes a product but first rips off the RFID tag or prevents it fromsignalling the storage cabinet's RFID sensor as it's taken out, thedecrement in weight signals that the product has gone. Thus, the RFIDtechnology verifies the weight sensor technology and vice versa. TheRFID tagging can also be used for the batch/lot control management of aparticular part, i.e. identifying a specific batch/lot number to theuser that takes the product.

In a further embodiment, more than one type of part/commodity can bestored on a weight sensor (load cell). The RFID tag identifies whichpart has been taken and the system knows the expected weight change ofthe parts taken. For example, if part A weighs 10 g and Part B weighs 7g and the user tags 2× part A and 1× part B it knows from the RFID tagsthat the total weight taken from the bin should be 27 g. If it is notthen the system reports that there is a variance.

In a further embodiment, RFID tagging also allows the system to checkhow long an item has been taken away and used for. For example, a toolsuch as a drill can be RFID tagged, and when it is taken from thestorage cabinet, the system knows the time and also the time it isreturned. This not only keeps a check of when an item needs to bere-calibrated but also the amount of time an employee has been using anitem. This, for example, helps to ensure employees are not exposed totoo much vibration from drill usage.

7. In a further embodiment, the system can generate a negative usagereport. Over a time period that is set by the user (for example 3 days)a report can be generated, indicating any users that have negative usage(i.e. user that have put more of a product back than they have takenaway over the given period). This report assists in identifying usersthat are potentially tampering with the system.

For example for the usage date of two users below (2^(nd) and 4^(th)rows), there are negative readings that can be reported:

User Product Usage Time John Brown ABC 2 Feb. 12, 2007 John Brown ABC −3Feb. 13, 2007 Fred Jones EFG 1 Feb. 14, 2007 Fred Jones EFG −10 Feb. 13,2007 Anthony Clarke ABC 1 Feb. 12, 2007 Anthony Clarke ABC 2 Feb. 13,2007

Report Inputs

Date: To      from      Time Period      days

Report Format

User Product Aggregated Usage John Brown ABC −1 Fred Jones EFG −9

In a further embodiment, the system can store (in the databaseaccessible by CS PC and associates with user ID) user size information,to restrict access to bins to specific users (who must enter their ID),or light up bins for the sizes of that specific user. This helps ensureusers take the correct size products e.g. respirators, gloves, shoesetc., enhancing safety.

What is claimed is:
 1. A method carried out in a stock monitoringsystem, comprising: providing a stock monitoring system including: ahousing, one or more doors disposed in or on the housing, at least oneor more container(s) for stock items, located within the housing, eachof the at least one of the one or more container(s) having associatedtherewith a weight sensor for providing a weight signal(s) indicative ofthe current weight of each of the at least one or more container(s), theat least one or more container(s) including a plurality of bins orcompartments and the weight sensor is associated with the plurality ofbins and/or compartments and provides a weight signal indicative of thecombined weight of the plurality of bins or compartments, and controlcircuitry, coupled for communication with the weight sensor(s);receiving one or more weight signals; determining, for the at least oneof the one or more container(s), the number of stock items removed fromthe container(s) by the user, from the weight signal(s) indicative ofthe combined weight of the plurality of bins or compartments.
 2. Themethod of claim 1, wherein the stock monitoring system further includesone or more door(s) disposed in the housing and one or more sensor(s)for sensing the condition of the one or more door(s) and providing adoor closed signal indicative of the one or more door(s) having beenclosed by a user.
 3. The method of claim 2, wherein the method furthercomprises receiving a door closed signal.
 4. The method of claim 3,wherein the step of determining the number of stock items removed fromthe container(s) includes determining from the weight signal(s)occurring during a predetermined sensing period, the predeterminedsensing period being dependent upon the door closed signal.
 5. Themethod of claim 4, wherein the predetermined sensing period comprises afirst predetermined time period after the door closed signal and thestep of determining the number of stock items removed from thecontainer(s) includes: determining a current average weight of thecontainer by averaging the weight signals over the predetermined sensingperiod; determining the weight difference for the container, the weightdifference being the difference between the current average weight andthe previously determined average weight; and dividing the weightdifference by a weight unit stored in memory in association with anidentifier for the container, thereby obtaining the number of stockitems removed from the container by the user.
 6. The method of claim 1,wherein the stock monitoring system further comprises a user ID sensor,adapted to be activated by a user and, wherein the method furthercomprises: obtaining a user ID from the user Ill sensor upon activationby a user; determining if the user ID obtained is valid.
 7. The methodof claim 6, wherein the stock monitoring system further comprises one ormore electrically controlled locks associated with the door(s), thelock(s) being electrically controllable such that the door(s) are ineither a locked or releasable condition, the control circuitry beingcoupled for communication with the locks, wherein the method furthercomprises: priming the doors for opening if door open conditions aremet, whereby the door(s) are in said releasable condition.
 8. The methodof claim 7, wherein the door open conditions comprise: the obtained userID is a valid ID, the user ID obtained is different from the previouslyobtained user ID; and the predetermined sensing period has elapsed;wherein the predetermined sensing period comprises a secondpredetermined time period after the door closed signal, different fromthe first predetermined time period.
 9. The method of claim 7, furthercomprising: activating the lock(s) so that the door(s) are in a lockedcondition, if the door(s) have not been opened by the user within athird predetermined time period after the doors have been primed foropening.
 10. A stock monitoring system, comprising: a housing; one ormore doors disposed in or on the housing; a sensor for sensing thecondition of the door(s) and providing a door closed signal indicativeof the door(s) having being closed; one or more containers for stockitems, located within the housing, the one or more containers havingassociated therewith a weight sensor for providing a weight signalindicative of the current weight of the container; and control circuitrycoupled for communication with the weight sensor(s); wherein the atleast one or more container(s) include a plurality of bins orcompartments and the weight sensor is associated with the plurality ofbins and/or compartments and provides a weight signal indicative of thecombined weight of the plurality of bins or compartments.
 11. A stockmonitoring system according to claim 10, further comprising: a means foractivating the stock monitoring, by a user; a user ID sensor, adapted tobe activated by a user, and one or more electrically controlled locksassociated with the door(s), the lock(s) being electrically controllablesuch that the door(s) are in either a locked or releasable condition,the control circuitry being coupled for communication with the locks.12. A stock monitoring system, comprising: a housing, one or more doorsdisposed in or on the housing, a sensor for sensing the condition of thedoor(s) and providing a door closed signal indicative of the door(s)having been closed by a user; at least one or more container(s) forstock items, located within the housing, each of the at least one of theone or more container(s) having associated therewith a weight sensor forproviding a weight signal(s) indicative of the current weight of each ofthe at least one or more container(s), the at least one or morecontainer(s) including a plurality of bins or compartments and theweight sensor is associated with the plurality of bins and/orcompartments and provides a weight signal indicative of the combinedweight of the plurality of bins or compartments; and control circuitry,coupled for communication with the weight sensor(s), wherein the controlcircuitry is operable to: receive a door closed signal; receive one ormore weight signals; and determine, for the at least one or morecontainer(s), the number of stock items removed from the container(s) bythe user, from the weight signal(s) occurring during a predeterminedsensing period, the predetermined sensing period being dependent uponthe door closed signal.
 13. The system of claim 12, wherein thepredetermined sensing period comprises a first predetermined time periodafter the door closed signal.
 14. The system of claim 12, furthercomprising: a means for determining the number of stock items removedfrom the container(s) by: determining a current average weight of thecontainer by averaging the weight signals over the predetermined sensingperiod; determining the weight difference for the container, the weightdifference being the difference between the current average weight andthe previously determined average weight; dividing the weight differenceby a weight unit stored in memory in association with an identifier forthe container, thereby obtaining the number of stock items removed fromthe container by the user.
 15. The system of claim 12, furthercomprises: a user ID sensor, adapted to be activated by a user andoperable for obtaining a user ID from the user ID sensor upon activationby a user and determining if the user ID obtained is valid.
 16. Thesystem of claim 15, wherein user ID sensor is a swipe card reader, andobtaining a user ID comprises extracting a user ID from a swipe cardupon swiping by a user.
 17. The system of claim 15, wherein user IDsensor is a Dallas key sensor, and obtaining a user ID comprisesextracting a user ID from a Dallas key upon activation of the Dallas keysensor by a user using the Dallas key.
 18. The system of claim 17,wherein the door open conditions comprise: the obtained user ID is avalid ID, the user ID obtained is different front the previouslyobtained user ID; and the predetermined sensing period has elapsed,wherein the predetermined sensing period comprises a secondpredetermined time period after the door closed signal, different fromthe first predetermined time period.
 19. The system of claim 15, whereinthe stock monitoring system further comprises one or more electricallycontrolled locks associated with the door(s), the lock(s) beingelectrically controllable such that the door(s) are in either a lockedor releasable condition, the control circuitry being coupled forcommunication with the locks, wherein the wherein the control circuitryis operable for: priming the doors for opening if door open conditionsare met, whereby the door(s) are in said releasable condition.
 20. Themethod of claim 1, wherein the one or more doors comprise the lid(s) ofthe compartment(s).
 21. The method of claim 7, wherein the one or moredoors comprise the lid(s) of the compartment(s).
 22. The stockmonitoring system of claim 10, wherein the one or more doors comprisethe lid(s) of the compartment(s).
 23. The stock monitoring system ofclaim 11, wherein the one or more doors comprise the lid(s) of thecompartment(s).
 24. The stock monitoring system of claim 12, wherein theone or more doors comprise the lid(s) of the compartment(s).